The American constitutional system is famously designed to guard against tyranny. Many observers think it will now face a major test because of the ascent of President-elect Trump, who has a history of ignoring norms and conventions that constrain lesser men. Norms such as don’t lie; don’t commit sexual assault; don’t commit tax fraud. Buoyed by his popularity, the Republican Party is now on the verge of controlling all three branches of government, a relative rarity in American politics. Unified government puts pressure on the system of checks and balances that is part of the constitutional design; it also allows for quick and decisive action. What should we expect in coming months?

The first casualty might be informal norms, such as the filibuster in the Senate. This rule allows minorities of 40 (out of 100) Senators to block action on legislation and on appointments. Might the Democrats used the filibuster to block a Trump-nominated candidate for the Supreme Court? The rule has already been weakened under the Obama administration, when Democrats responded to Republican obstructionism by eliminating its application to judicial appointments below the Supreme Court. If the Democrats seek to block a Republican appointee, the Senate majority could just eliminate the rule. One constraint on this happening, however, is that some Republicans might secretly value the rule when it comes to legislation. Many Republicans have serious issues with some of Trump’s proposals, and may want to blame the Democrats for blocking it. So I expect that the filibuster will survive, at least as far as legislation is concerned.

Federalism is also likely to be an interesting area to watch in coming years. Federalism in the United States is a constantly shifting set of arrangements, with policy and funding flowing upwards and downwards over time. Federalism limits the reach of an overly centralized government, and so has led some states and cities to resist, or at least fail to cooperate with, federal efforts targeting undocumented immigrant workers. If Donald Trump keeps his campaign promises (hardly a sure thing), immigration will set off a conflict over federalism. Another area for possible change is drug policy. Some 29 American states have legalized marijuana in some form, but it remains a dangerous drug according to the national government. Most drug laws are enforced by states in our system, but there could be a crackdown on this “nullification” of federal law.

Another topic that gathered a good deal of attention in the first weeks after the election was the Emoluments clause, an obscure bit of constitutional text that reads that “No Person holding any Office of Profit or Trust under [the Constitution], shall, without the Consent of the Congress, accept of any present, Emolument, Office, or Title, of any kind whatever, from any King, Prince, or foreign State.” This somewhat cryptic text is not completely clear but people believe that it may refer to financial benefits that flow from a foreign government. Because Trump’s business empire may involve arrangements with state-owned firms in other countries, he may be receiving benefits from foreign governments. Some have even suggested that he will be violating the Constitution on day one in office. Congress may have to pass a “Trump law” that will allow him to maintain his business ties, but this raises the risk that he mixes his business affairs with those of the government.

A final topic that may be of interest to the global constitutional law community, given Trump’s promises to withdraw from the North American Free Trade Agreement (NAFTA) and his questioning of NATO, concerns the status of treaties. Entering into a formal treaty requires the President to negotiate it and the Senate to approve it; but many agreements, including NAFTA, are passed in domestic law as ordinary statutes. For the latter, it is likely that the Congress would have to be involved in withdrawing or ending a treaty. For Senate-approved treaties (like NATO), the law is less clear. In the 1979 case of Goldwater v. Carter, a group of senators argued that the ending of a treaty required the same process as its entry into force. That would mean that two-thirds of the Senate would be required to approve a withdrawal from NATO. But the Supreme Court decided to dismiss the case, though there was disagreement on the basis for the dismissal. One opinion suggested that it was a political question, not fit for resolution by the Court; another suggested that the case required a formal resolution from the Senate as a whole. The bottom line is that it is not clear how much room Trump has to exit treaties, but it may be easier to break international arrangements than it is to enter them. Let’s hope the country doesn’t get broken in the process.

Tom Ginsburg is Leo Spitz Professor of International Law, Ludwig and Hilde Wolf Research Scholar, and Professor of Political Science. Before entering law teaching, he served as a legal adviser at the Iran-U.S. Claims Tribunal, The Hague, Netherlands, and he continues to work with numerous international development agencies and foreign governments on legal and constitutional reform.